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981.
We report a mitochondrial targeted redox probe (MitoRP) that comprises a nitroxide radical (TEMPO) moiety and coumarin 343. Using isolated mitochondria in the presence/absence of substrates and inhibitors of oxidative phosphorylation, we demonstrated that MitoRP is a useful probe to monitor the electron flow associated with complex I. 相似文献
982.
Tao Liu Jianhong Chen Shinji Sugihara Yasushi Maeda 《Colloid and polymer science》2012,290(8):763-767
Hydration of poly(N-vinylcaprolactam) microgels was investigated by near-infrared (NIR) and mid-infrared (MIR) spectroscopy. The thermosensitive microgels were prepared by emulsion polymerization, and turbidity, dynamic light scattering, and differential scanning calorimetry measurements were carried out. In MIR spectra, carbonyl bands consist of three components due to double, single, and zero hydrogen-bonding carbonyl groups as verified by density functional theory calculations. The relative intensities changed critically at the volume phase transition temperature upon heating. In NIR spectra, two absorbance peaks around 5,900?cm?1 were observed, which can be assigned to the first overtone of C–H bands. Both of them undergo red shifts during the phase transition in a similar way to that of fundamental bands in MIR spectra. The result suggests that NIR spectroscopy may be a new general method that can provide new information for research on hydration of thermosensitive microgels. 相似文献
983.
Yasushi Nishihara Eiji Inoue Shintaro Noyori Daisuke Ogawa Yoshiaki Okada Masayuki Iwasaki Kentaro Takagi 《Tetrahedron》2012,68(24):4869-4881
In this paper, we explore the copper/palladium-cocatalyzed cross-coupling reactions of 1-aryl-2-trimethylsilylethynes with aryl iodides, bromides, and chlorides as coupling partners, to furnish unsymmetrically disubstituted ethynes in moderate to excellent yields. Various aryl iodides were subjected to reaction under the optimized conditions with 5 mol % of Pd(PPh3)2 and 50 mol % of CuCl. The steric properties of the aryl iodide proved more influential to the outcome of the cross-coupling reaction than electronic factors. In addition, we succeeded in synthesizing unsymmetrical diarylethynes using two different aryl iodides in one-pot. Furthermore, under the same reaction conditions with 10 mol % of PdCl2, 40 mol % of P(4-FC6H4)3, and 50 mol % of CuCl as catalyst, we succeeded in synthesizing unsymmetrical diarylethynes from various aryl bromides. Finally, we explored reactions with aryl chlorides and duly discovered that unsymmetrical diarylethynes were obtainable in moderate to good yields when 10 mol % of Pd(OAc)2, 10 mol % of (?)-DIOP, and 10 mol % of CuCl were used. These reactions proceed through a direct activation of a carbon–silicon bond in alkynylsilanes by CuCl to generate the corresponding alkynylcopper species via transmetalation from silicon to copper. Mechanistic investigations on the reaction of alkynylsilanes with aryl bromides confirmed that the trimethylsilyl bromide generated in situ retarded both transmetalation steps between CuCl and alkynylsilane, and between palladium(II) species formed by oxidative addition and alkynylcopper species. 相似文献
984.
Yamaguchi T Matsumoto S Masumizu T Takechi S Ishida T Takeshita K Kansui H Kunieda T 《Chemical & pharmaceutical bulletin》2012,60(5):639-646
The various biological activity of dihydropyrazines(DHPs)due to the radical generation potency has been described in previous papers. Detailed data about radical species generating be mentioned here. The electron spin resonance (ESR) spin-trapping technique revealed that DHPs generate free radical species such as ·OH, ·OOH, ·CHR(2) and ·CR(3). Oxygen radicals and two carbon-centered radicals were detected as adducts of the spin traps DMPO and DBNBS, respectively. All the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)- and 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS)-adducts of compounds DHP-1-8 exhibited approximately the same signal patterns, with various levels of intensity depending on the substituent of the dihydropyrazine ring. The ESR signal intensity of DHPs also increased remarkably upon addition of Cu(2+), resulting that the effects of DHPs were enhanced. 相似文献
985.
Tetsuo Ogawa 《Phase Transitions》2013,86(7-8):673-681
Photoinduced nucleation processes, called photoinduced domino processes, via excited electronic states are discussed theoretically for a one-dimensional arrangement of deformable molecules using a model composed of localized electrons and lattices. We show that the global structural transition by photoexcitation only at a molecule (site) is possible in the adiabatic and diabatic limits. An intermediate regime between these limits is investigated; an analytical treatment and a numerical calculation are presented taking into account the nonadiabatic electronic transition, i . e ., the Landau-Zener-type transition. In this regime, the domino dynamics can be terminated halfway ( i . e ., a finite - size domain appears) in contrast to the "all-or-nothing" domino dynamics ( i . e ., a photoinduced domain vanishes or grows up to the system size) in the adiabatic and diabatic limits. 相似文献
986.
Hongyu An Susumu Takada Takumi Sannomiya Shinji Muraishi Ji Shi Yoshio Nakamura 《Applied Physics A: Materials Science & Processing》2013,113(1):31-35
Magnetic properties and internal stresses of AlN(20 nm)/[CoPt(2 nm)/AlN(20 nm)]5 multilayer structure deposited at different substrate temperatures by dc magnetron sputtering have been studied. It is found that with increasing the substrate temperature from room temperature to 400 °C, in-plane magnetic anisotropy field of the film becomes smaller, and the out-of-plane magnetization becomes stronger. Especially when the film is deposited at substrate temperature of 400 °C, the out-of-plane magnetization becomes as strong as the in-plane magnetization. On the other hand, the total in-plane residual stress of the film changes gradually from compressive to tensile. The compressive intrinsic stress is generated during deposition process and decreases with increasing the substrate temperature. After annealing at high temperatures, the films show strong perpendicular magnetic anisotropy. With increasing the annealing temperature, the in-plane thermal stress also increases and becomes dominant, which is considered to result in the perpendicular magnetic anisotropy of the films. 相似文献
987.
988.
Takayuki Yamazaki Akira Miyazaki Taikan Suehara Toshio Namba Shoji Asai Tomio Kobayashi Haruo Saito Yuichi Urushizaki Isamu Ogawa Toshitaka Idehara Svilen Sabchevski 《Hyperfine Interactions》2012,212(1-3):141-147
Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS, about 203 GHz) is an important observable but all previous measurements of Ps-HFS had been measured indirectly using Zeeman splitting. There might be the unknown systematic errors on the uniformity of magnetic field. We are trying to measure Ps-HFS directly using sub-THz radiation. We developed an optical system to accumulate high power (about 10 kW) radiation in a Fabry-Pérot resonant cavity and observed the positronium hyperfine transition for the first time. 相似文献
989.
Makina Saito Makoto Seto Shinji Kitao Yasuhiro Kobayashi Masayuki Kurokuzu Yoshitaka Yoda 《Hyperfine Interactions》2012,205(1-3):87-90
Langmuir-Blodgett (LB) films of octadecanoyl hydroxamic acid (C18N) complexed with Fe3?+? ions have been prepared at various subphase pH values. The LB films consisting of different number of layers were investigated by 57Fe conversion electron M?ssbauer spectroscopy (CEM) at room temperature. The CEM detector contained a piece of α-iron, enriched with 57Fe, using as an internal standard. The M?ssbauer pattern of the C18N/Fe LB films is a doublet with parameters δ = 0.35?mm/s and Δ = 0.74?mm/s. A gradual increase of the relative occurrence of the doublet compared to the sextet of the internal standard was observed with the increasing number of layers, indicating the nearly uniform distribution of Fe among the LB layers. 相似文献
990.
In this paper, we find a basis for the space S k (?? 0(4)) of cusp forms of even weight k for the congruence subgroup ?? 0(4) in terms of Eisenstein series. As an application, we obtain formulas for r 4s (n), the number of ways to represent a nonnegative integer n as a sum of 4s integral squares. 相似文献